如何让 UITextView 检测主题标签？

Question

我知道 UITextView 默认可以检测到 URL，但我怎样才能让它检测到 hashtags(#)？

打字时不需要检测主题标签，但是 viewDidLoad 文本设置在 UITextView 中，所以我想将主题标签检测为颜色或其他东西。

我一直在使用 ActiveLabel，但那只适用于 UILabel，我需要 UITextView 具有的滚动功能。

Answer 1

一个选择是使用 NSAttributedString，像这样...

func convertHashtags(text:String) -> NSAttributedString {
    let attrString = NSMutableAttributedString(string: text)
    attrString.beginEditing()
    // match all hashtags
    do {
        // Find all the hashtags in our string
        let regex = try NSRegularExpression(pattern: "(?:\s|^)(#(?:[a-zA-Z].*?|\d+[a-zA-Z]+.*?))\b", options: NSRegularExpressionOptions.AnchorsMatchLines)
        let results = regex.matchesInString(text,
            options: NSMatchingOptions.WithoutAnchoringBounds, range: NSMakeRange(0, text.characters.count))
        let array = results.map { (text as NSString).substringWithRange([=10=].range) }
        for hashtag in array {
            // get range of the hashtag in the main string
            let range = (attrString.string as NSString).rangeOfString(hashtag)
            // add a colour to the hashtag
            attrString.addAttribute(NSForegroundColorAttributeName, value: UIColor.redColor() , range: range)
        }
        attrString.endEditing()
    }
    catch {
        attrString.endEditing()
    }
    return attrString
}

然后像这样分配你的 attributedText...

let myText = "some text with a #hashtag in side of it #itsnoteasy"
self.textView.attributedText = convertHashtags(myText)

Answer 2

这应该适合你

创建一个新的 swift 文件，名称任意(UITextViewHashtagExtension.swift)

在下面插入此代码：

import UIKit

extension UITextView {

func resolveHashTags(){

    // turn string in to NSString
    let nsText:NSString = self.text

    // this needs to be an array of NSString.  String does not work.
    let words:[NSString] = nsText.componentsSeparatedByString(" ")

    // you can't set the font size in the storyboard anymore, since it gets overridden here.
    let attrs = [
        NSFontAttributeName : UIFont.systemFontOfSize(17.0)
    ]

    // you can staple URLs onto attributed strings
    let attrString = NSMutableAttributedString(string: nsText as String, attributes:attrs)

    // tag each word if it has a hashtag
    for word in words {

        // found a word that is prepended by a hashtag!
        // homework for you: implement @mentions here too.
        if word.hasPrefix("#") {

            // a range is the character position, followed by how many characters are in the word.
            // we need this because we staple the "href" to this range.
            let matchRange:NSRange = nsText.rangeOfString(word as String)

            // convert the word from NSString to String
            // this allows us to call "dropFirst" to remove the hashtag
            var stringifiedWord:String = word as String

            // drop the hashtag
            stringifiedWord = String(stringifiedWord.characters.dropFirst())

            // check to see if the hashtag has numbers.
            // ribl is "#1" shouldn't be considered a hashtag.
            let digits = NSCharacterSet.decimalDigitCharacterSet()

            if let numbersExist = stringifiedWord.rangeOfCharacterFromSet(digits) {
                // hashtag contains a number, like "#1"
                // so don't make it clickable
            } else {
                // set a link for when the user clicks on this word.
                // it's not enough to use the word "hash", but you need the url scheme syntax "hash://"
                // note:  since it's a URL now, the color is set to the project's tint color
                attrString.addAttribute(NSLinkAttributeName, value: "hash:\(stringifiedWord)", range: matchRange)
            }

        }
    }

    // we're used to textView.text
    // but here we use textView.attributedText
    // again, this will also wipe out any fonts and colors from the storyboard,
    // so remember to re-add them in the attrs dictionary above
    self.attributedText = attrString
}

}

要使用它，您可以这样做：

self.textView.text = "This is an #example test"
self.textView.resolveHashTags()

更新为 Swift 4.0：

extension UITextView {

    func resolveHashTags() {

        // turn string in to NSString
        let nsText = NSString(string: self.text)

        // this needs to be an array of NSString.  String does not work.
        let words = nsText.components(separatedBy: CharacterSet(charactersIn: "#ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_").inverted)

        // you can staple URLs onto attributed strings
        let attrString = NSMutableAttributedString()
        attrString.setAttributedString(self.attributedText)

        // tag each word if it has a hashtag
        for word in words {
            if word.count < 3 {
                continue
            }

            // found a word that is prepended by a hashtag!
            // homework for you: implement @mentions here too.
            if word.hasPrefix("#") {

                // a range is the character position, followed by how many characters are in the word.
                // we need this because we staple the "href" to this range.
                let matchRange:NSRange = nsText.range(of: word as String)

                // drop the hashtag
                let stringifiedWord = word.dropFirst()
                if let firstChar = stringifiedWord.unicodeScalars.first, NSCharacterSet.decimalDigits.contains(firstChar) {
                    // hashtag contains a number, like "#1"
                    // so don't make it clickable
                } else {
                    // set a link for when the user clicks on this word.
                    // it's not enough to use the word "hash", but you need the url scheme syntax "hash://"
                    // note:  since it's a URL now, the color is set to the project's tint color
                    attrString.addAttribute(NSAttributedStringKey.link, value: "hash:\(stringifiedWord)", range: matchRange)
                }

            }
        }

        // we're used to textView.text
        // but here we use textView.attributedText
        // again, this will also wipe out any fonts and colors from the storyboard,
        // so remember to re-add them in the attrs dictionary above
        self.attributedText = attrString
    }
}

Answer 3

对于Swift 3 +

 extension UITextView {
        
        func convertHashtags(text:String) -> NSAttributedString {
            
            let attr = [
                NSFontAttributeName : UIFont.systemFont(ofSize: 17.0),
                NSForegroundColorAttributeName : clr_golden,    
                NSLinkAttributeName : "https://Laitkor.com"
             ] as [String : Any]

        
        let attrString = NSMutableAttributedString(string: text)
        attrString.beginEditing()
        // match all hashtags
        do {
            // Find all the hashtags in our string
            let regex = try NSRegularExpression(pattern: "(?:\s|^)(#(?:[a-zA-Z].*?|\d+[a-zA-Z]+.*?))\b", options: NSRegularExpression.Options.anchorsMatchLines)
            let results = regex.matches(in: text,
                                                options: NSRegularExpression.MatchingOptions.withoutAnchoringBounds, range: NSMakeRange(0, text.characters.count))
            let array = results.map { (text as NSString).substring(with: [=10=].range) }
            for hashtag in array {
                // get range of the hashtag in the main string
                let range = (attrString.string as NSString).range(of: hashtag)
                // add a colour to the hashtag
                //attrString.addAttribute(NSForegroundColorAttributeName, value: clr_golden , range: range)
                attrString.addAttributes(attr, range: range)
            }
            attrString.endEditing()
        }
        catch {
            attrString.endEditing()
        }
        return attrString
    }
}

在您的 class 中添加 UITextViewDelegate 并像这样使用

 self.tv_yourTextView.delegate = self
 self.tv_yourTextView.attributedText = tv_yourTextView.convertHashtags(text: "This is an #museer test")

委托功能

func textView(_ textView: UITextView, shouldInteractWith URL: URL, in characterRange: NSRange) -> Bool {
    print("hastag Selected!")
    return true
}

-> 修改@Wez 答案

Answer 4

对于swift 4.0

extension UITextView {

    func resolveHashTags() {

        // turn string in to NSString
        let nsText = NSString(string: self.text)

        // this needs to be an array of NSString.  String does not work.
        let words = nsText.components(separatedBy: CharacterSet(charactersIn: "#ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_").inverted)

        // you can staple URLs onto attributed strings
        let attrString = NSMutableAttributedString()
        attrString.setAttributedString(self.attributedText)

        // tag each word if it has a hashtag
        for word in words {
            if word.count < 3 {
                continue
            }

            // found a word that is prepended by a hashtag!
            // homework for you: implement @mentions here too.
            if word.hasPrefix("#") {

                // a range is the character position, followed by how many characters are in the word.
                // we need this because we staple the "href" to this range.
                let matchRange:NSRange = nsText.range(of: word as String)

                // drop the hashtag
                let stringifiedWord = word.dropFirst()
                if let firstChar = stringifiedWord.unicodeScalars.first, NSCharacterSet.decimalDigits.contains(firstChar) {
                    // hashtag contains a number, like "#1"
                    // so don't make it clickable
                } else {
                    // set a link for when the user clicks on this word.
                    // it's not enough to use the word "hash", but you need the url scheme syntax "hash://"
                    // note:  since it's a URL now, the color is set to the project's tint color
                    attrString.addAttribute(NSAttributedStringKey.link, value: "hash:\(stringifiedWord)", range: matchRange)
                }

            }
        }

        // we're used to textView.text
        // but here we use textView.attributedText
        // again, this will also wipe out any fonts and colors from the storyboard,
        // so remember to re-add them in the attrs dictionary above
        self.attributedText = attrString
    }
}

如何让 UITextView 检测主题标签？

How to make UITextView detect hashtags?

uitextview

ios

swift

这应该适合你